There are already several satellite navigation systems on Earth, such as China's Compass satellite navigation system, the United States' GPS, Russia's GLONASS and Europe's Galileo satellite navigation system, etc. Every world power wants to have its own satellite navigation system that can be fully autonomous, and even countries like Japan and India are building their own satellite navigation systems. And for the space powers, the competition for satellite navigation systems has extended to the moon.
At the "China Space Day" on April 24 this year, Wu Yanhua, deputy director of the National Space Administration, said that China is now demonstrating the construction of a "lunar communication and navigation satellite constellation", which is a lunar navigation and positioning satellite system similar to Beidou Navigation.
But China is not the first country in the world to propose the construction of a lunar satellite navigation system, in May last year, the European Space Agency (ESA) launched a plan to establish a satellite navigation and communications satellite network in orbit around the moon, nearly a year earlier than China.
But this aspect of the fastest moving or the United States, on June 28 this year, the United States to the lunar orbit successfully launched a lunar probe CAPSTONE ("apex" or "capstone"), this satellite is only the size of a microwave oven is considered the world's first lunar navigation satellite, which indicates that the United States in the lunar navigation system has entered a substantial stage of implementation, to create a lunar GPS United States and leading.
Weighing only 25 kilograms, the U.S. Rocket Lab's Electron rocket and its Photon upper stage sent it to a ballistic lunar transfer orbit at a speed of nearly 11 kilometers per second, taking the Vertex first to The orbital position is the line of the exact equilibrium of the gravitational forces of the Earth and the Moon, which is extremely stable and requires less energy for the orbital position, and is considered an ideal staging area for lunar and other missions that have never been attempted before. will operate in that orbit for two months, after which it will enter a navigation orbit.
The satellite is also the first successful launch of a lunar probe by the U.S. in nearly a decade. As a pathfinder for the U.S. Artemis "Return to the Moon" program, it will not rely on the ground to give instructions for navigation during its flight, but will navigate itself based on a satellite currently flying in lunar orbit and the position of the Earth's moon.
Many friends may be wondering, the moon is not inhabited, there is no car driving, the demand for navigation applications is minimal, why do we have to fight a complex satellite navigation system? Isn't this a bit of a waste?
In fact, if only explore the front of the Moon, then the navigation satellites operating around the Earth is sufficient to meet the navigation needs, but in the poles and back of the Moon can not use the Earth's navigation satellites, and humans are entering the era of lunar exploration and development, the future of human lunar activities will be more and more, China's next step will be the implementation of Chang'e 6, 7, 8 lunar exploration activities, it is known that Chang'e 7 will carry a jump detector, its travel on the lunar surface is also required to navigate the positioning.
China has also put forward plans for manned lunar landings and joint construction of lunar research stations with Russia, which also require more accurate lunar navigation functions, and Europe and the United States have their own plans for lunar exploration, which also have navigation needs.
However, at this stage of human exploration of the Moon is still in the early stage, the requirements for navigation accuracy is not high, the use of it is not much, so different lunar navigation satellite system may consist of more than 1 to 3 satellites, and three satellites will be able to do more accurate positioning, but also uninterrupted transmission of lunar surface communication signals to the Earth, but with the future of human exploitation of the Moon and even the arrival of the era of immigration, will require higher standards of accuracy and signal transmission capabilities, which requires more navigation satellites to complete.
Science.com, June 30, "U.S. launches Capstone satellite to pave way for moon landing program"
April 24 article of the Central Broadcasting Network, "National Space Administration: the construction of a constellation of lunar communication and navigation satellites around the moon is being debated